"Stem borer. The species produces a fusiform swelling at the stem terminal and are on almost every stem terminal."

[note from same source: a related, but distinct Epiblema, probably the one now clarified to be E. minutana, "...forms part of a complex with E. strenuata ...The 2 species can be separated by their biology... [The non-strenuata species] bores in the main stem and sometimes into the lateral branches of the ragweed but does not infest the stem terminals to produce the fusiform swellings characteristic of E. strenuata. Ragweed stems are more commonly infested in the fall season by this species.]